Calccis 4+

The main new feature in this version is support for matrixes.

Calccis can perform the following matrix calculations:
- addition
- subtraction
- multiplication (also scalar * matrix)
- inverse (1/x)
- determinant
- transposition
- dot product for vectors

Inputting matrixes is somewhat limited. It is not possible to enter complex or rational values into the matrixes, yet.

Other improvements include, among others:
- Scientific formatting of numbers (-1.24E-4) works more nicely.
- Multiplications and divisions of complex numbers that only have a real or imaginary part use cartesian values for calculation. This change avoids small numerical errors caused by converting the values to polar format, and the use of trigonometrical functions.
- Changing the angle unit (Deg -> Rad or vice versa) updates the angle units of complex values in the stack.
- There is an edit function, which copies the selected (or topmost) value of the stack to the edit buffer. This feature is currently available for matrixes and plain numerical values only, not for complex numbers or fractions.